Question

if a number 573 xy is divisible by 9 then what is the value of x + Y

Answer 1

If 573xy is divisible by 90, then y = 0. So we have 573x0.

For any number to be divisible by 9, the sum of the digits should be 9. Here we have 5+7+3 = 15, 1+5 = 6.

Therefore, x should be 9–6 = 3.

So the actual number is 57330.

The sum of x+y = 3.

Answer 2

Since 630 is the only number divisible by 90, in the set of three digit numbers starting with 6 . Since the number is divisible by 90, the last step gives,

6xy - 630 = 0

6xy = 630

Therefore x = 3, y = 0

So x + y = 3.